Green’s Dictionary of Slang

(US black/gang) to fight as a gang, to attack as a group; thus wolfpacking n.

1969		(ref. to 1950s) R.L. Keiser Vice Lords 50: Fighting which results when a group of club members goes out to jump on anyone they can find is wolfpacking.
1989		Columbia SC State B 12 Aug. 6: Other shopping centres are plagued by litter [...] left in the parking lots, where teenagers ‘wolf-pack,’ sit around on their cars and then leave.
1992		Bentley & Corbett Prison Sl. 90: Wolf Pack When three or more inmates attack one [...] generally associated with established gang activity.